B&W makes some of the world’s highest-fidelity loudspeakers. As global competition increases, management sees an increasing role for electromagnetic simulation to improve design characteristics and shorten design cycles.
B&W targets the very high end of the audio reproduction market. Its speakers are widely used in recording studios and in the consumer market with innovations such as hi-fi speakers for MP3 players and flat hi-fi speakers to go with plasma TVs.
The company has used electromagnetic design software for well over a decade. Its first major foray into this area started in the mid 1990s, when engineers tried to create their own “reverse finite element analysis” software in conjunction with the University of Brighton to calculate backwards from the ideal sound characteristics to find a suitable design. The complexity of this problem meant that the work petered out, but it made B&W purchase its first professional electromagnetic design software, the Vector Fields Opera package.
The Opera software plays a major role when engineers want to make the most of the magnetic characteristics of a speaker motor to achieve as high and as linear a field as possible to bring speaker sensitivity to its maximum.
This is a particular issue for the high-frequency tweeter elements of a sound system. One of the major limitations affecting tweeter speakers is behind the speaker, in the tube or space that absorbs the sound emanating from the rear of the diaphragm. Good acoustic performance demands an air hole in the motor system, which inevitably leads to a compromise in the maximum flux levels and achievable sensitivity. The Opera tool helps B&W tailor the magnetic performance of the motor early in the design cycle. Once initial concepts are produced, B&W still relies greatly on real-world listening tests to prove and enhance a design.
The company also uses Opera to find solutions to more complex dynamic problems. In development, in conjunction with a Vector Fields applications engineer, is a generic model that will help B&W overcome problems caused by the dynamically changing impedance of the voice coil as it moves nearer or farther to the steel magnetic material in the air gap. This changing impedance gives rise to distortion, typically heard as a roughness of voice. In the past, B&W solved this issue empirically by the application of conductive material to reduce the change. However, the problem is non-linear and complex to solve. Thus, the new model will allow B&W to quickly settle on optimal designs for each loudspeaker motor design.
Professional electromagnetic design software – the Opera—helps B&W develop high fidelity speaker systems for products for recording studios as well as MP3 players and High Definition TVs.
The Opera software tool, from Vector Fields Inc., helps B&W engineers tailor the magnetic performance of the acoustic motor system early in the design cycle. Good acoustic performance requires a balanced compromise between maximum flux levels and achievable sensitivity.
Vector Fields, Inc.
http://www.vectorfields.com/
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